Meteoroid Streams as Probes of the Subsurface Regions of Comets

✍ Scribed by John J. Matese; Patrick G. Whitman

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 522 KB
• Volume: 109
• Category: Article
• ISSN: 0019-1035
• DOI: 10.1006/icar.1994.1091

✦ Synopsis

Whipple recognized the importance of the rocket-like volatization forces on a comet nucleus when he formulated his conglomerate model. For near-parabolic comets, a determination of an unbound original orbit when only gravitational forces are included is commonly believed to be indirect evidence of large neglected nongravitational forces. A comet can be given energy either by a symmetric positive transverse nongravitational force or an asymmetric radial nongravitational force, enhanced during the postperihelion phases. We present evidence describing those new Oort cloud comets which are most likely to have experienced large nongravitational forces. A correlation between enhanced episodic outgassing and the passage of these comets through well-known meteor streams is investigated. These results are interpretable as the catalytic increase in volatility as the impacting meteoroids penetrate any surviving mantle and probe the icy subsurface regions. If there exists trapped gas, either in subsurface pockets or at a crystalline/amorphous-ice interface, then it is much more likely to erupt and expose adjacent underlying fresh volatiles when the meteoroids impact the comet, diminishing the tensile strength of the subsurface crystalline layer. 1994 Academic Press, Inc.